Golf clubs take various forms, for example a wood, a hybrid, an iron, a wedge, or a putter, and these clubs generally differ in head shape and design (e.g., the difference between a wood and an iron, etc.), club head material(s), shaft material(s), club length, and club loft.
Woods and hybrids generally have a longer shaft and lower loft than irons and wedges. Thus, a golf ball struck with a wood or a hybrid generally travels a greater distance than a golf ball struck with an iron or a wedge. In addition to shaft length and club loft, golf ball spin rate affects distance. At impact between the golf club and the golf ball, spin is imparted on the golf ball in the form of backspin and sidespin. While a certain amount of backspin is needed to generate sufficient lift to keep the ball in the air, too much backspin can negatively affect overall carry distance. For example, when comparing two ball flights struck with the same club but having different amounts of backspin, the ball with too much backspin will curve upward more rapidly (uplift or balloon) to a higher apex and subsequently fall more steeply (with a steeper descent angle) than the ball flight of the ball having less (or more optimal) backspin. Accordingly, the ball having too much backspin travels a shorter distance. The optimal amount of backspin, however, generally depends on the specific golf club.
As opposed to lower lofted clubs (e.g., woods, hybrids, etc.), with higher lofted clubs (e.g., wedges, 9-iron, 8-iron, 7-iron, etc.), greater amounts of backspin can be beneficial, as the focus of these clubs is less on distance and more on accuracy and, a steeper descent angle generated by excess backspin can assist with stopping the ball on a green. Ball spin is also generally affected by impact position on the golf club face. For example, a golf ball struck on the club face towards the toe and crown of the club head has lower backspin than a ball struck in the center or “sweet spot” of the club face. A golf ball struck on the club face towards the heel and sole of the club head has greater backspin than a ball struck on the sweet spot of the club face. As another example, a golf ball struck on the club face towards the toe or towards the heel of the club head generally has more sidespin than a ball struck on the sweet spot of the club face. Variable amounts of backspin and sidespin imparted on the golf ball result in inconsistent distance and direction based on club face impact position.
While golf clubs have a variety of known designs, there is a need for reducing or better controlling golf ball spin, or spin rate in lower lofted golf clubs to maximize distance. There is also a need to reduce the variability of spin imparted on the golf ball on off-center hits (e.g., golf ball impact on the golf club face other than the sweet spot) by improving spin rate consistency in contact areas across the club face.